Your article on Peter Lilley joining the House of Commons select committee on energy and climate change (Report, 25 October) drew attention to his recent attack on the 2006 Stern review on the economics of climate change. However, you failed to point out that Lilley's pamphlet was published by the Global Warming Policy Foundation, which actively lobbies against government climate change policies while refusing to reveal its sources of funding.

Lilley's central criticism is that the Stern review, led by Nicholas Stern, a former chief economist at the World Bank and a well-known authority on public policy analysis, exaggerated the risks posed by unmitigated climate change. However, this claim is based on Mr Lilley's false assertion that the review used a single discount rate to assess how climate change might affect future economic growth. In fact, in such analyses discount rates will depend on consumption or income levels at any point in time, and these levels will depend on climate change policies and impacts. Thus any growth path involves many discount rates and such rates will depend on assumptions about the severity of damages from climate change and the weights attached to consumption or income losses that occur. The review explicitly examined a whole range of assumptions about these issues.

The review's main conclusion, that the risks of inaction on climate change are far greater than the costs of reducing greenhouse gas emissions, is robust, confirmed many times over by subsequent research. By contrast, Mr Lilley's pamphlet is riddled with embarrassingly bad economics and flawed science.Bob WardGrantham Research Institute on Climate Change and the Environment, LSE